As one of the methods for synthesizing liquid fuels from natural gas, a GTL (Gas to Liquid: liquid fuel synthesis) technique of reforming natural gas to produce a synthesis gas including carbon monoxide gas (CO) and hydrogen gas (H2) as main components, synthesizing hydrocarbons using a catalyst with this synthesis gas as a source gas by the Fischer-Tropsch synthesis reaction (hereinafter referred to as “FT synthesis reaction”), and further hydrogenating and refining the hydrocarbons to produce liquid fuel products, such as naphtha (raw gasoline), kerosene, gas oil, and wax, has recently been developed.
The liquid hydrocarbons synthesized by the FT synthesis reaction are separated from the catalyst slurry, which has solid catalyst particles suspended in the liquid hydrocarbons, before being transferred to a refining process in the subsequent process where the hydrocarbons are converted into naphtha, kerosene, etc. Conventionally, as a device to separate liquid hydrocarbons from a catalyst slurry, a method which passes the hydrocarbons through filters is suggested, as described in, for example, Patent Document 1.